Ischemia/reperfusion (I/R) is a pathophysiologic process that occurs during hemorrhagic shock, liver resection and liver transplantation. Baicalein, the main active ingredient of the Scutellaria root, exerts anti-inflammatory and anti-apoptotic properties in the setting of I/R injury in the heart and brain. However, the role of baicalein in liver I/R injury and its regulatory mechanisms remain poorly understood. This study was designed to evaluate the effects of baicalein in a model of liver I/R in mice and to explore the possible mechanisms. Baicalein (100 mg/kg) was intraperitoneally injected 1 h before warm ischemia. Pretreatment with baicalein protected against liver I/R injury, as indicated by the decreased serum aminotransferase levels and the reduced histopathologic abnormalities. Baicalein also significantly reduced cellular hepatic apoptosis in response to I/R injury. Moreover, pretreatment with baicalein significantly inhibited nuclear factor-kappa B (NF-kappa B) activation and the subsequent proinflammatory cytokine production, and decreased leukocyte infiltration. In vitro studies, baicalein treatment inhibited the proinflammatory cytokine production via the modulation of NF-kappa B signaling pathway in lipopolysaccharide-stimulated macrophages. Taken together, these results suggest that baicalein could protect against liver I/R injury via inhibition of inflammation by down-regulating NF-kappa B activity, and suppression of cellular hepatic apoptosis. (C) 2014 Elsevier B.V. All rights reserved.